Run Map Error

So when I try to test my map in run map, it shows this:

** Executing…
** Command: “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\bin\vbsp.exe”
** Parameters: -game “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod” “C:\Users\gspan\Desktop\rp_mythicalmrp_desert_v2-1_propfix.vmf”

Valve Software - vbsp.exe (Mar 14 2016)
2 threads
materialPath: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\materials
Loading C:\Users\gspan\Desktop\rp_mythicalmrp_desert_v2-1_propfix.vmf
ConVarRef mat_reduceparticles doesn’t point to an existing ConVar
***need to set $abovewater for material dev/dev_water2_cheap
***need to set $abovewater for material dev/dev_water2_cheap
Error! Variable “$surfaceprop” is multiply defined in material “nature/blendrockgravel001a”!
Error! Variable “$surfaceprop” is multiply defined in material “nature/blendrockgravel001a”!
Brush 10615: MAX_MAP_BRUSHSIDES
Side 4
Texture: TOOLS/TOOLSNODRAW

** Executing…
** Command: “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\bin\vvis.exe”
** Parameters: -game “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod” “C:\Users\gspan\Desktop\rp_mythicalmrp_desert_v2-1_propfix”

Valve Software - vvis.exe (Dec 9 2014)
2 threads
reading c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix.bsp
Error opening c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix.bsp

** Executing…
** Command: “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\bin\vrad.exe”
** Parameters: -game “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod” “C:\Users\gspan\Desktop\rp_mythicalmrp_desert_v2-1_propfix”

Valve Software - vrad.exe SSE (Dec 9 2014)

  Valve Radiosity Simulator     

2 threads
[Reading texlights from ‘lights.rad’]
[45 texlights parsed from ‘lights.rad’]

Loading c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix.bsp
Error opening c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix.bsp

** Executing…
** Command: Copy File
** Parameters: “C:\Users\gspan\Desktop\rp_mythicalmrp_desert_v2-1_propfix.bsp” “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\maps\rp_mythicalmrp_desert_v2-1_propfix.bsp”

The command failed. Windows reported the error:
“The system cannot find the file specified.”

** Executing…
** Command: “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\hl2.exe”
** Parameters: -game “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod” -toconsole -dev -console +sv_lan 1 +map “rp_mythicalmrp_desert_v2-1_propfix” -steam

At the end of all that, it says

The command failed. Windows reported the error:
“The system cannot find the file specified.”

I followed the instructions at https://developer.valvesoftware.com/wiki/Saving_and_Compiling
but to no avail.

I just have no idea how to fix it. Hopefully all you guys can help?

Your map is too big / has too many brushes.

So how would I alter the BSP file as the wiki says?

You would need access to the full source code of the Source Engine and edit however the engine processes and compiles .VMF files into the .BSP format.

Use propper

More exactly this propper: https://github.com/tuxxi/propper-2013/releases/

Ok, I tried propper, but this is what the error is now:

** Executing…
** Command: propper
** Parameters: -game “C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod” “c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix”

Propper 0.32. Originally written by Carl Foust, fixed and compiled for SDK Base 2013 by tuxxi. Adapted from vbsp.exe by Valve Software. (May 25 2016)
2 threads
materialPath: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\materials
Loading c:\users\gspan\desktop\rp_mythicalmrp_desert_v2-1_propfix.vmf
ConVarRef mat_reduceparticles doesn’t point to an existing ConVar
***need to set $abovewater for material dev/dev_water2_cheap
***need to set $abovewater for material dev/dev_water2_cheap
Error! Variable “$surfaceprop” is multiply defined in material “nature/blendrockgravel001a”!
Error! Variable “$surfaceprop” is multiply defined in material “nature/blendrockgravel001a”!
Could not locate ‘GameData’ key in c:\program files (x86)\steam\steamapps\common\garrysmod\garrysmod\gameinfo.txt
Patching WVT material: maps/rp_mythicalmrp_desert_v2-1_propfix/nature/blendrocksand008c_wvt_patch
Patching WVT material: maps/rp_mythicalmrp_desert_v2-1_propfix/nature/blendsandrock004a_wvt_patch
Patching WVT material: maps/rp_mythicalmrp_desert_v2-1_propfix/nature/blendrockgravel001a_wvt_patch
Patching WVT material: maps/rp_mythicalmrp_desert_v2-1_propfix/nature/blendrockdirt002a_wvt_patch
ProcessBlock_Thread: 0…1…2…3…4…5…6…7…8…9…10 (2)
ProcessBlock_Thread: 0…1…2…3…4…5…6…7…8…9…10 (1)
Chop Details…done (0)
Find Visible Detail Sides…
Merged 462 detail faces…done (0)
Merging details…done (0)
WARNING: node without a volume
WARNING: node without a volume
WARNING: node without a volume
WARNING: node without a volume
WARNING: node without a volume
8 seconds elapsed

I went to the propper wiki and set up a new run command with those params and code. Did I do something wrong? I also added the game configuration for propper.

WARNING: node without a volume is an invalid brush and you need to remake it, did you try and use propper on the whole level ?